How was 'pi ' discovered in the first place?

You can thank the Greeks and their obsession with Geometry for this one. They found when you divided the circumference of a circle by its area I think you get 3.141...... or pi. Actually the ratio Pi is obtained by dividing the circumference of any circle by the length of the diameter. There is also some evidence which possibly indicates that this ratio (Pi) was known to the ancient Egyptians ca 2500 b.c.e.